To calculate the percent error for the number of drinks sold, we need to know the actual value or the expected value of the number of drinks sold and the measured value or the value that we obtained. If we don't have the actual or expected value, we cannot calculate the percent error.
Assuming we have the expected value and the measured value, we can use the following formula to calculate the percent error:
Percent error = [(measured value - expected value) / expected value] x 100%
Without knowing the expected value or the measured value, we cannot calculate the percent error.